Apparatus for measuring the heat opacity of photographic film



' Nov. 2 1926.

v. c. DE YBARRONDOY APPARATUS FOR MEASURING THE HEAT OPACI-TY 0F PHOTOGRAPHIC FILM Filed Dec. e 1921 INI/ENTOKYI'. VINCENT C DEYBAREONDO, Ev 7;

ATTO/ENE Y5.

Patented Nov. 2, 19261 UNITED STATES PATENT OFFICE.

VINCENT C. DE YBARBONDQ OF LOS ANGELES, CALIFORNIA.

Application flled DecemberB, 1921. Serial 110. 520,448.

This invention relates to the photographic industry and particularly to apparatus for comparing the heat opacity of translucent materials with a standard plate of a known heat opacity.

It is an object of my invention to provide an apparatus of this character in which objects of translucent material may be interposed between a source of heat and a thermometric registering device, the intensity of the heat radiations being allowed to pass through the translucent object, due to its heat opacity noted upon the registering device.

Other objects and advantages will be made evident hereinafter.

Referring to the drawing which is for illustrative purposes only:

Fig. 1 is a side elevation of a device embodymg my invention, being partially in section, as indicated by the line 11 of Fig. 2. i 1

Fig. 2 is a sectional view taken substantially upon a plane represented by the line 22 of Fig. 1.

Fig. 3 is a diagrammatic representation of the device.

As shown in the drawing, I provide a case 11 providing chambers 12 and 13 divided by a partition member 14. Within the chamber 12 I mount a reflector 15 having situated centrally therein a heating element 20 in circuit, as best shown in Fig. 3, with an electricalenergy source 21, a rheostat 22, and an ammeter 23. The electricalsource 21 is preferably the 110 V. lighting system and I provide a two-point contact plug receptacle 25 upon the side 26 of the case 11 for connecting into the lighting circuit by means of a drop cord. j

The radiations of heat from the element 20 are converged by the reflector 15 as indicated by the dotted lines .30 and when not thereb'y rendered substantially ara-llel, they maybe passedinto a rectifying ens 31 which is preferably of a substanceof slight interference with the passage of heat radiations,

and which lens causesthe parallelization -"of the heat ray's as indicated by the dottedlines 32., The parallel rays are adapted to pass through a screen holder 33 and-apertures provided. in vertical rwalls 34 which extend do wnwardly from the top 35 of'the case 11 to provide a film slot 36. The arallel rays may also be-intercepted by a p ate 37 of a .beconveniently noted b desired standard opacitywhich is mounted upon slides" 38 and 39 and adapted to be moved into a position of interceptance, as illustrated in Fig. 2, by pulling out a knob which connects through a rod 47 to the frame 46 holding the plate 37.

After passing through the aperture in walls 34 forming the slot 36- the parallel rays are received by a converging lens50 which directs them against a thermo-reactive element such as a thermopile 51. The thermopile 51 is in circuit with a galvanometer 52 mounted in a box 53 on the top of the case 11 in a position wherein the readings of the pointer 54 upon the dial 55 thereof may the operator. My device is especia 1y ada ted to the testing of exposed film in or er that the amount off development which such film i shall be given may be accurately determined. The device is also of importance in determining the intens'ity and duration of light to which film should be subjected in the printing thereof as it has been found that each ne ative film requires separate consideration 1n the printing operation.

My device is essentially useful in the testing' of new or unexposed film to determine the amount or thickness of the emulsion layer thereupon, or to check up the uniformity of unexposed film. My device eliminates the use ofllght rays in the testing of opacities using heat radiations instead thereof thereby makin it possible to test unexposed film without anger of fogging.

Owing to the variable conditions that exist in certain heat-reactive elements I provide-a means of regulating the heat source to give a desired reading ofthe galvano meter 52in circuit with the thermopile 51 to correspond to a certain heat opacity of film. In acomplishing this regulation ofthe heat source 1 move the plate 37 into the position in which. it isshown in Fig. 2, so that the heat rays will be intercepted thereby. The plate 37 is of a known opacity'and preferably corresponding to the opacity to which the films are to be developed to give the best results. The heat radiations passing through the plate 37 are tempered, ue to the heat opacity of the plate, and upon being received by the'thermopile 51, cause-an electric current to flow in the circuit 60 indicated in Fig. 3, in which circuit both the-thermopile 51 and the galvanometer 52 are situated. By

manipulating the rheostat 22 to increase or decrease the energization of the element 20 the int-Lnsity of the radiations finally reaching the thermopile 51 may be ad usted to give a reading of the galvanometer corresponding to the heat opacity of the plate 37.

then passing therethrough will be received by the thermopile 51 and if the film corresponds to the heat opacity as represented by the plate 37 the reading 'of the pointer 54' upon the dial 55 will be the same as'the reading given by the plate 37 in the ad ustment )f the source of heat 20. A condition of heat opacity in a film being tested above or below that of the standard of heat opacityas represented by the plate 37 will be faithfully indicated by higher or lower reading of the pointer 54 upon the dial 55 which may be calibratedto read the different degrees of heat opacity directly.

When a luminous heat source is used at 20 I provide a screen which is placed in the screen frame 33 to bsorb the light rays but allow'the heat rays to pass uninterrupted. This screen may consist of a glass vessel containing a solution of carbon bisulplnde which has a characteristic of interfering with the passage of light rays. A known solution of the character referred to 1s preared by the admixture of iodine with carhon bisulphide.

I claim as my invention:

1. An apparatus for measuring the heat opacity of light-sensitive photographlc material said apparatus comprising: means for passing heat radiations through a light-sensitive photographic material without passing light rays thereto; and a thermometric de vice for receiving the heat radiations passed through the light-sensitive material.

2. In an apparatus for measuring the heat opacity of light-sensitive photographic material, the combination of: a heat-radiating body; a thermometric device adapted to receive heat radiations fromLsaid body, said apparatus ,being adapted to receive a lightsensitive photographic material between said body and said device; and a light screen forpreventing the passage of light rays from said heat-radiating body to said light-sensitive material.

, 3. In an apparatus for measuring the heat Opacity of. hght-sensitive photographic ma-. terial, the .combination of; a heat-radiating body, a thermopile; means for focussing heat radiations emanating from said body upon said therlnopile; an electrical indicatlng instrument connected to said thermopile,

said apparatus l eing adapted to receive a light-sensitive photographic material between said body and said thermopile; and a light screen for preventing the passage of light rays from said heat-radiating body to said light-sensitive material.

a. In an apparatus for measuring the heat opacity of translucent materials, the combination of: a heat radiating body; a thermopile; means for focusingthe heat radiations from said body upon said thermopile; means for iuter 'iosing a translucent object between said body and said thermopile; a light screen for prei'enting the passage of light rays from said heat radiating body to said trans lucent object; a galvanometer in circuit with said thermopile to register the variations of heat to which said thermopile is subjected; an object of known heat opacity to be interposed between said thermopile and said body; and means for varying the intensity of the heat radiations projected through said object of known opacity to bring said galvanometer to a point of registration corresponding to said known opacity.

5. In an apparatus for measuring the heat opacity of translucent materials, the combination of: a heat radiating body; a thermopile; means for focusing the heat radiations from said body upon said thermopile; means for interposing a translucent object between said body and said thermopile; a galvanom meter in circuit with said thermopile to register the variations of heat to which said thermopile is subjected; an object of known heat opacity removably interposed between said thermopile and said body; means for varying the intensity of heat radiations pro jectcd through said object of known opacity to bring said galvanometer to 'a point of registration corresponding to said known opacity; and a screen holder whereby light absorbing filter means may be projected into the path of said heat radiations.

6. In an apparatus for measuring the heat opacity of translucent materials, the combination of: a heat radiating body; a thermopile; a reflector adaptedto convergingly direct the heat radiations from said body towards saidthermopile; a rectifying lens to parallelize said heat radiations;-

means for interposing a translucent object in the path of said parallel heat radiations; a galvanometer in circuit with said thermopile to register the variations of heat to -whichisaid thermopile is subjected; an object of known heat opacity removably interposed between said thermopile and said heat radiating body; and meansfor varying the heat radiations projected through said ob: ject' of known opacity to bring said combination of a heat radiating body; a

al- -vano'meter to a point ofregistration co rethermopile; a reflector adapted to convergingly direct the heat radiations from said body towards said thermopile; a recti ing lens to parallelize said heat radiations; means for interposing a translucent object I in the path of said parallel heat radiations;

path of said parallel to register the ;var1ations means for converging said heat rays upon said thermopile; a 'galvanometer'in circuit with said thermopile to register the variations of heat to which said thermopile issubjected; an object of known heat opacity removably interposed between said thermopile and said heat radiating body; means for varying the heat radiations projected through said object oi? known bpacity to bring said galvanometer to a point of registration corresponding to said known opacity; and a screen holder whereby light absorbing. filter means may be projected into the path ofsaid heat radiations.

8. In. an ap aratus for measuring the heat opacity oi translucent materials, the

combination of: a heat radiating body; a

vanometer in circuit sponding to said knownopacityQ the .- 9. In an ap aratus for measuring translucent materials, the

heat opacity o combination of: an electric heating element;

a thermopile; a reflector adapted to convergingly direct the heat radiations from I said element toward-said thermopile; atrectifying lens to parallelize'said' heat radiati'o ns; means for interposing a translucent ob ect 1n the path of said parallel heat radiations; means for converging said heat rays upontsaid thermopile; a galvanometer in circuitlwith said thermopile;- to register the variations of heat to which said thermopile is subjected; an object of known heat opacity adapted tojbe interposed'between said thermopile and said element; and

" means in'circuit with said element foradju'sting the energizationtthereof to bring said galvanometer to a point of registrationf corresponding to said known opacity.

' 10. In an apparatus for measuring the heat opacity of translucent materials, the 9 combination of: an electric heating element; a thermopile; a reflector adapted to conver ingly direct the heat radiations from sai element toward said thermopile; a rectifying lens to parallelize' said heat radiations; a converging lens to direct said parallelized radiations against said the opile; means for interposing a translucen object in the path of-said parallel heat radiations; j

a galvanometer in circuit with said thermo-- pile to register the variations of heat to which said thermopile is subjected; an object of known "heatopacity adapted to be interposed between said thermopil'e and said element; and means in circuit with said ele,-

ment for 'adjusting the'energization thereof to bring said galvanometer to a point of registration corresponding to said known opacity; 4 a

11. n an a? aratus for measuring the heat opacity o 'ght-sensitive photographic materials, the com ination of: a heat radiating body; a thermometric device adapted to' receive heat radiations from said body; means for interposi ng a light-sensitive photographic object between said body and said thermometric device; a body of standard heat pacity removably interposed between sai heat radiating body and said thermometric device; means for preventing light rays reaching said light-sensitive hbtographic object; and means for varymg the heat of said heat radiating body to give a desired reading of said thermometric device when'said body of standard opacity is interposed between said heat radiating body and said thermometric device.

12. In an apparatus for measuring the heat opacity of translucent materials, the combination of: a heat radiating body; a

' thermometric device; means for focusing the heat radiations from said heat radiating body vupon said thermometric device; means i for interposin a translucent object between said body an said thermometric device;,a body'of standard heat opacity removably interposed between said heat. radiating body and said thermometric dev'ce; and means for varying the heat of sai heat radiatin body to give a desired reading of sai thermometric device when said body of standard opacity is interposedlbetwn said .-heat radiating body and said thermometric device; Y

. In-testimo'n whereof,-I have hereunto set 'my hand at s Angeles; California, 30th day of Novembe'r, 1921. y

this

mam Ca n YBaimonno. a 

